This is a note to let you know that I've just added the patch titled
tipc: fix unexpected link reset due to discovery messages
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
tipc-fix-unexpected-link-reset-due-to-discovery-mess.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 3364f02fe9c1830005c21a21ab04cdeea05ff3a0
Author: Tung Nguyen <tung.q.nguyen@xxxxxxxxxxxxxx>
Date: Thu Jan 5 06:02:51 2023 +0000
tipc: fix unexpected link reset due to discovery messages
[ Upstream commit c244c092f1ed2acfb5af3d3da81e22367d3dd733 ]
This unexpected behavior is observed:
node 1 | node 2
------ | ------
link is established | link is established
reboot | link is reset
up | send discovery message
receive discovery message |
link is established | link is established
send discovery message |
| receive discovery message
| link is reset (unexpected)
| send reset message
link is reset |
It is due to delayed re-discovery as described in function
tipc_node_check_dest(): "this link endpoint has already reset
and re-established contact with the peer, before receiving a
discovery message from that node."
However, commit 598411d70f85 has changed the condition for calling
tipc_node_link_down() which was the acceptance of new media address.
This commit fixes this by restoring the old and correct behavior.
Fixes: 598411d70f85 ("tipc: make resetting of links non-atomic")
Acked-by: Jon Maloy <jmaloy@xxxxxxxxxx>
Signed-off-by: Tung Nguyen <tung.q.nguyen@xxxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/net/tipc/node.c b/net/tipc/node.c
index 49ddc484c4fe..5e000fde8067 100644
--- a/net/tipc/node.c
+++ b/net/tipc/node.c
@@ -1179,8 +1179,9 @@ void tipc_node_check_dest(struct net *net, u32 addr,
bool addr_match = false;
bool sign_match = false;
bool link_up = false;
+ bool link_is_reset = false;
bool accept_addr = false;
- bool reset = true;
+ bool reset = false;
char *if_name;
unsigned long intv;
u16 session;
@@ -1200,14 +1201,14 @@ void tipc_node_check_dest(struct net *net, u32 addr,
/* Prepare to validate requesting node's signature and media address */
l = le->link;
link_up = l && tipc_link_is_up(l);
+ link_is_reset = l && tipc_link_is_reset(l);
addr_match = l && !memcmp(&le->maddr, maddr, sizeof(*maddr));
sign_match = (signature == n->signature);
/* These three flags give us eight permutations: */
if (sign_match && addr_match && link_up) {
- /* All is fine. Do nothing. */
- reset = false;
+ /* All is fine. Ignore requests. */
/* Peer node is not a container/local namespace */
if (!n->peer_hash_mix)
n->peer_hash_mix = hash_mixes;
@@ -1232,6 +1233,7 @@ void tipc_node_check_dest(struct net *net, u32 addr,
*/
accept_addr = true;
*respond = true;
+ reset = true;
} else if (!sign_match && addr_match && link_up) {
/* Peer node rebooted. Two possibilities:
* - Delayed re-discovery; this link endpoint has already
@@ -1263,6 +1265,7 @@ void tipc_node_check_dest(struct net *net, u32 addr,
n->signature = signature;
accept_addr = true;
*respond = true;
+ reset = true;
}
if (!accept_addr)
@@ -1291,6 +1294,7 @@ void tipc_node_check_dest(struct net *net, u32 addr,
tipc_link_fsm_evt(l, LINK_RESET_EVT);
if (n->state == NODE_FAILINGOVER)
tipc_link_fsm_evt(l, LINK_FAILOVER_BEGIN_EVT);
+ link_is_reset = tipc_link_is_reset(l);
le->link = l;
n->link_cnt++;
tipc_node_calculate_timer(n, l);
@@ -1303,7 +1307,7 @@ void tipc_node_check_dest(struct net *net, u32 addr,
memcpy(&le->maddr, maddr, sizeof(*maddr));
exit:
tipc_node_write_unlock(n);
- if (reset && l && !tipc_link_is_reset(l))
+ if (reset && !link_is_reset)
tipc_node_link_down(n, b->identity, false);
tipc_node_put(n);
}
